1. Field of the Invention
This invention relates to a spinning machine having a yarn treating carrier provided with a yarn piecing mechanism and a yarn package doffing mechanism therein and moving along a rail provided on a frame of a spinning machine so as at least to stop at a predetermined spindle for carrying out a yarn piecing operation to the spindle and a yarn package doffing operation.
2. Description of the Related Art
Generally, a spinning machine is provided with a yarn forming and winding device, as unit spindle, including at least a yarn drafting mechanism, a yarn forming mechanism, a yarn detecting mechanism, and a yarn winding mechanism. A plurality of these unit spindles, i.e., the yarn forming and winding devices, are arranged along a longitudinal direction of a frame of the machine with a certain distance interposed therebetween to form a spinning machine.
A spinning machine is further provided with a yarn treating carrier including a yarn piecing mechanism and a yarn package doffing mechanism therein. This which moves along a rail provided on a frame of a spinning machine so as at least to stop at a predetermined spindle for carrying out a yarn piecing operation to the spindle and a yarn package doffing operation thereof.
In one aspect of a conventional spinning machine, a yarn treating carrier including a yarn piecing mechanism and a yarn package doffing mechanism is controlled to move to a predetermined position and to stop thereat by detecting a dog provided at a predetermined position on the yarn forming and winding device utilizing an encoder which can discriminate an absolute position of the dog and which is provided on the yarn treating carrier.
The moving system of the yarn treating carrier as mentioned above is, for example, disclosed in Japanese Unexamined Patent Publication No. 61-266622.
The system explained above, however, requires the same number of dogs, each having a different pattern, as the number of the spindles in the yarn forming and winding device.
Further, the system, in order to detect a pattern of a dog when the yarn treating carrier moves along the rail, requires a dog having a significantly elongated portion in a moving direction. Moreover, when the number of dogs is increased, a problem arises in that the number of bit of a dog to be detected will be increased, resulting a broader width of the dog.
On the other hand, in this system, when a moving direction of the yarn treating carrier is determined, it is required to input not only information about a current position at which the yarn treating carrier is exists but also information about a yarn treatment requirement to a moving direction indicating circuit.
Thus, when the moving direction indicating circuit is provided on the yarn treating carrier, it is necessary to transmit information requiring the yarn treatment of each spindle from a machine frame side to the yarn treating carrier while when the moving direction indicating circuit is provided on the machine frame side, it is necessary to transmit the information about a current position at which the yarn treating carrier exists from the carrier to the machine frame as well as to transmit the moving direction indicating signal from the machine frame to the carrier.
In any case, since the number of signals is increased, and the number of wirings for transmitting the above signals between the carrier and the machine frame and the number of connecting portions for connecting the wirings are increased, another problem arises in that the reliability of the machine will be reduced.
On the other hand, in order to transmit these signals to a predetermined position accurately, expensive transmitting terminals should be used.
In another conventional spinning machine, the yarn treating carrier is controlled in such a way that when the yarn treating carrier detects a spindle at which a yarn treatment operation, is required, it stops at the spindle and carries out a predetermined yarn treating operation.
After the yarn treating operation has finished, the yarn treating carrier selects a moving direction to which it moves next.
The moving system of the yarn treating carrier as explained above, is disclosed in, for example, Japanese Examined Patent Publication No. 60-47937 and Japanese Examined Patent Publication No. 61-60016.
In this system, however, a problem arises in that since an occasion in which an operational pattern, for example, a moving direction of the yarn treating carrier, can be changed occurs only when the yarn treating carrier stops at one end of the machine frame or at the time when the carrier starts to move after the yarn treating operation has finished at the spindle to which the yarn treatment was required, immediate yarn treatment cannot be expected at a spindle at which the yarn treatment requirement occurs while the yarn treating carrier is moving along the rail.
In still another conventional spinning machine, the yarn treatment requiring signal is output and indicated at each spindle respectively and, therefore, when the yarn treating carrier detects a spindle at which a yarn treatment operation is required, it shops at the spindle and carries out a predetermined yarn treating operation.
The moving system of the yarn treating carrier as explained above is disclosed in, for example, Japanese Unexamined Patent Publication No. 60-47937.
In this system as mentioned above, the yarn treating carrier successively moves to the spindles adjacently arranged and when it detects the spindle to be treated it stops thereat to perform the necessary yarn treatment.
This system, however, has another problem in that it is difficult to make the starting position of the yarn treating carrier deceleration longer than a pitch P formed between the adjacently arranged spindles.
Note that when the pitch P formed between the adjacently arranged spindles is set at 230 mm, the distance for deceleration of the yarn treating carrier is from 100 mm to 130 mm, since a distance is required for acceleration at the start of movement.
If, when the distance for deceleration is set at more than 130 mm, it is difficult to increase the maximum speed since there is no distance for acceleration resulting a starting operation beginning with a decelerating operation.
Therefore, when a spinning machine starts a yarn forming operation and a yarn treating carrier also moves from one spindle to the next spindle and stops in sequence, since the yarn treating carrier starts to be decelerated before it is sufficiently accelerated, it is apparent that the yarn treating carrier always moves at a low speed and thus a problem arises in that the response time for yarn treating operation to the spindle at which a yarn treatment is required is usually prolonged and the operational efficiency is extremely low.
On the other hand, since a moving direction of the yarn treating carrier cannot be reversed except when it takes a position at one of the ends of the machine frame, when a yarn treatment operation is just required at a spindle located in an opposite direction to a direction in which the yarn treating carrier is now moving, a problem arises in that the waiting time for the yarn treatment will be prolonged.
In another conventional spinning machine, a yarn treating carrier carries out a yarn piecing operation only in response to a yarn treatment signal output from a spindle, the amount of yarn wound of a yarn package, i.e., a diameter of a yarn package, of each spindle is different from that of another spindle since the amount of the yarn wound on the yarn package is determined by the total time of yarn breakage.
In this system, although the yarn winding operation is sequentially stopped for spindles where the yarn package is full, the doffing operation is carried out at the same time in the machine after all of the yarn packages in all spindles are full, or the yarn package doffing operation is carried out when a yarn package of a predetermined spindle in the same machine frame is full.
Accordingly, other problems arise in that, in the former case, the operational efficiency is low, while in the latter case, a variation occurs in the amount of yarn wound on the yarn packages.